How Does Fitbit Figure Out that I am Sleeping?

Sleep is a very component of a person’s health. The duration, timing and pattern of your sleep impacts your emotional health, metabolism, mental well-being, performance and even your memory. One easy way to track your sleeping habits and quality is through trackers. Fitbit trackers are reliable devices that can do this for you too.

But how do these devices do that?

Sleep Tracking with Fitbit

Fitbit tracks your sleep by analyzing your heart rate pattern and a few of your movements that are indicative of sleep. But you must have the tracker on in your sleep for it to do that. When you haven’t moved for an hour or so the device assumes that you are sleeping. By using movements such as rolling over, it confirms that you are asleep.

When you are asleep the device tracks the beat-to-beat variations in your heart. This is called heart rate variability (HRV). This analysis spits out a few numbers in the end. Changes in these numbers tell the user how they transitioned between light, deep and REM sleep stages.

Most Fitbit trackers will tell you three things about your sleep: duration, quality and restoration. Duration tells you how long you slept. Quality tells you about the different stages of your sleep. While restoration tells you how relaxed you were in your sleep. Usually a score between 90 and 100 means that your sleep was excellent. A score lower than 60 means that you didn’t sleep well.


To sum it up there is no separate device installed in Fitbit or any other tracker to track your sleep. It does that by monitoring your activity and heart rate pattern. The device then uses these numbers and gives you a score. The score tells you how well you slept. Fitbit and other trackers do their best to give you accurate information but it’s still not medical grade, so take it with a pinch of salt.

WRBLS – Get Serious. Get Watches.
Enable registration in settings - general